1. Field of Invention
This invention relates to a manual miter saw with angle adjustment arrangement having a carrier, a turntable which is mounted to the carrier so as to be able to turn relative to it and which forms a workpiece support surface, and a turntable fixing device for fixing the turntable relative to the carrier in certain reproducible angular positions within a working rant of possible angular positions.
2. Description of Related Art
Miter saws of the type under consideration have been known for a long time in various embodiments, generally in conjunction with the use of circular saws. Miter saws with angle adjustment are used, for example, in the form of circular table saws (U.S. Pat. No. 6,370,997) and also as combined crosscut saws and miter saws (U.S. Patent Application Publication Nos. 2002/0088327 A1 and 2004/0060412 A1). They are used to work all types of materials. One special application of these miter saws is in woodworking. This does not preclude the teaching of this invention being able to be used for miter saws of other applications, especially for working of plastics and metalworking.
Furthermore, generic miter saws are manual miter saws, the major functions of which (alignment, fixing, lowering, sawing) can be made to be decoupled from one another, in contrast to partially or fully automated miter saws in which these function are at least partially coupled to one another.
Miter saws of the type under consideration, conventionally, comprise a stationary carrier and a turntable which can be turned on or in the carrier, the workpiece to be worked coming to rest on the turntable and often also on a part of the carrier which is made as a workpiece support surface. A stop rail which is installed on the carrier generally protects the workpiece against slipping in the sawing process by the workpiece being pressed against the stop rail during the sawing process.
The turntable, which can turn around a vertical axis, at the same time, bears a holding device for the saw assembly so that, by turning the turntable, the saw assembly is moved at the same time in the same way. When the turntable turns out of its middle position, the cutting plane which is defined by the saw blade includes a saw angle, the miter angle, with the cutting plane which corresponds to the middle position. Thus, a miter cut can be made on the workpiece. The area in which the turntable can be swivelled out of its middle position thus defines the working area of the miter saw.
In order to be able to reliably make a miter cut, it is necessary to fix the turntable in the selected angular position. Various construction measures are known for this purpose. Conventionally, miter saws allow staggered and reproducible fixing of the turntable in defined angular positions within its working range, such as, for example, ±15°, ±30°, ±45°, and ±60° from the middle position. For example, a miter arc which runs parallel to the periphery of the turntable with miter notches at the defined angular positions is used to fix these angular positions. An elastic catch arm which is connected to the turntable enables the turntable to be fixed in the desired angular position by its locking in the miter notch (U.S Patent Application Publication No. 2002/0088327 A1). One alternative possibility for fixing this angular position is to provide a ball which is elastically supported on the turntable and which engages holes which are provided on the base in defined angular positions so that fixing takes place in this way (JP 11-226905 A, U.S. Pat. No. 5,207,141).
Moreover, generic miter saws are known in which defined angular positions which can be reproduced in stages can be continuously and jointly adjusted in a narrow area This continuous adjustment possibility is used only for fine calibration of the staggered angular positions for purposes of calibration, for which reason it is possible only within narrow limits around the zero position, but in no case in essential parts of the working range of the respective miter saw (U.S Patent Application Publication No. 2004/0079214 A1, European Patent Application EP 0 779 122 A2, U.S. Patent Application Publication No. 2003/0200852 A1).
Furthermore, a miter saw of the type under consideration is known in which the angular adjustment has two different possibilities for locking. In addition to the above described possibility of fixing the turntable only at certain angles relative to the carrier, it is then possible, for example, to fix the turntable in any angular position, for example, by an additional clamping device (U.S. Patent Application Publication No. 2004/0060412 A1). However, the continuously fixed angular position cannot be reproduced in the sense of a catch position which can be easily found again.
Furthermore, a partially automated miter saw is known which has a graduated circle on which the stops can be continuously moved and fixed (U.S Pat. No. 3,487,863). This partially automated miter saw comprises an attachment part which is connected securely to the base of the miter saw, with an opening and a switch which is provided in the opening. The angular position which is defined by the position of the stop which is fixed on the graduated circle can be reproduced by a pin which is elastically supported in the stop being pressed down and locking in the opening of the attachment part, with which, at the same time, the miter saw is activated in a manner which cannot be functionally separated, and a cut is made.